A conventional Integrated Circuit (IC) socket assembly is disclosed in Japanese Unexamined Patent Publication No. 2001-24370 (FIGS. 1 and 2). This IC socket assembly comprises a heat sink mounted on an IC package, which is received in a socket housing. A linear mounting member is rotatably attached to the IC socket. The heat sink is pressed against and fixed to the IC package by the linear mounting member.
Another conventional IC socket assembly is disclosed in Japanese Unexamined Patent Publication No. 2003-7942 (FIG. 3). This IC socket assembly comprises a socket housing that houses a great number of electrical contacts therein, a heat sink that abuts the upper surface of an IC package which is mounted on the socket housing, and a fixing member for fixing the heat sink to the socket housing. The fixing member comprises a heat sink support and a heat sink base. The fixing member presses the heat sink against the IC package from one side of a printed circuit board, on which the socket housing is mounted. Thereby, the heat sink is urged into close contact with the IC package.
The IC socket assemblies disclosed in the aforementioned Japanese Unexamined Patent Publications mount the heat sinks onto the IC sockets so that they are urged toward the IC packages only on one side of the printed circuit boards. In both conventional IC socket assemblies, the forces exerted by the members for fixing the heat sinks are applied to the housings, via the IC packages. These forces may cause warping of the housings, adversely affecting the coplanarity between the bottom surfaces of the housings and the printed circuit board. As a result, the reliability of the electrical connections between the bottom surface of the housing (circuit board mounting surfaces) and the printed circuit board is compromised.